The invention relates to aspirator apparatus, and more particularly relates to aspirator apparatus of the vacuum-operated type. In its most immediate sense, the invention relates to dental aspiration devices such as are used to aspirate body fluids and solids from a patient's mouth, and to methods for using such devices.
Dental procedures can cause solid matter (e.g. bone chips, tooth particles, tissue fragments, pieces of amalgam etc.) to enter fluids (e.g. saliva, blood, and cooling water) that are present in the patient's mouth. The solid matter is removed from the mouth to prevent the patient from swallowing or aspirating it, and removal of the solid matter necessarily entails removal of the fluids as well. When such fluids are withdrawn from the patient's mouth (as by a vacuum-powered saliva ejector or a high-speed saliva aspirator) this solid matter can cause difficulties for the dentist and even for the patient. One such difficulty is that the solid matter can clog the vacuum system. Another such difficulty is that the solid matter can build up upon the inside surfaces of the vacuum lines, thereby forming a base for the growth of biofilm that in turn promotes the growth of bacteria. For these reasons, it is known to provide a strainer unit behind the ejector or aspirator. The strainer unit separates the solid matter from the body fluids, protecting the vacuum system and making it more difficult for a biofilm to build up. Conventionally, the ejector or aspirator is disposable, but the strainer unit is not.
Existing strainer units have a number of disadvantages. First, existing FDA regulations do not require that strainer units be sterile; they need only be clean. And, even if a particular dentist is motivated to sterilize a strainer unit before connecting it to the vacuum system, existing strainer units can neither be easily emptied nor easily cleaned and sterilized. Hence, a strainer unit used during a dental procedure on a patient will likely be unsterile at the beginning of the procedure. In the worst case, the strainer unit will contain solid matter and/or body fluids from a prior patient. This poses the danger that bodily substances from a dental procedure performed earlier in a day may cross-contaminate (as by backflowing fluid into the patient's mouth) a patient undergoing a dental procedure later on that day. Second, existing strainer units are not versatile. (The saliva ejector shown in U.S. Pat. No. 3,890,712 is an example of such a non-versatile device.) They are designed to work only with a particular type of saliva ejector or aspirator, and cannot easily be used with another type. Third, existing strainer units are relatively expensive. (The Osseous Coagulum Trap now being sold through Quality Aspirators, Duncanville Tex., is an example of an expensive strainer unit.) Hence, if a dentist is motivated to use a sterile strainer unit for each patient, the dentist must make a considerable investment in strainer units and must incur increased operating expenses to clean and to sterilize them.
It would be advantageous to provide an improved strainer unit that would overcome these disadvantages.
Existing saliva ejectors and high-speed saliva aspirators also have disadvantages. One conventional saliva ejector, which has a strainer tip at its distal end, can become painfully embedded in the soft tissue of the patient's mouth. This is because the patient's flesh can seal off the holes in the strainer tip. When this happens, the vacuum to the saliva ejector causes the strainer tip and the patient's flesh to be tightly urged against each other. Similarly, a conventional high-speed saliva aspirator can likewise become wedged against the patient's flesh and cause damage to the tissue.
Finally, although conventional saliva ejectors, saliva extractors and similar dental tools are supplied in a "clean" state, they necessarily become less clean when contacted by the hand of the dentist or dental hygienist.
It would be advantageous to provide a saliva ejector and a saliva extractor, and a method for using such dental tools, that would overcome these disadvantages.
In accordance with the invention, a modularized aspiration system is provided. One component of the system is an all-plastic strainer unit. This strainer unit has three parts: a plastic strainer, a plastic strainer cap, and a plastic housing. The strainer has an open inlet end and an outlet end and a multiplicity of openings sized to permit fluids to pass out of the strainer and to retain solids within the strainer. The retainer cap is attached to the strainer and covers its inlet end, and has an inlet port where an aspirator device (such as a saliva ejector or a high-speed saliva aspirator) can be attached. The housing has an inlet end and an outlet end. The inlet end is shaped to receive the strainer so that the inlet end of the strainer faces the inlet end of the housing and the outlet end of the strainer faces the outlet end of the housing. The outlet end has an outlet port sized to fit onto a distal end of a conventional vacuum valve.
In preferred embodiments, the strainer unit is a dental strainer unit, the vacuum valve is a saliva ejector valve, the openings are sized to permit saliva, blood, and water to pass out of the strainer, and the strainer cap and strainer are removably secured within the housing. This makes it possible to adapt the strainer unit for attachment to almost any saliva removal device by mounting the strainer unit with a cap having an appropriately-sized male or female element. This also makes it possible to manufacture the strainer unit economically, since the number of parts required is small; the same strainer and housing can be used in all instances and only the cap (which is a comparatively small and inexpensive part) need be made in a variety of sizes.
Advantageously, and in preferred embodiments, the housing is transparent and non-rigid; transparency allows the dentist or dental hygienist to know if the strainer is becoming overfull, and non-rigidity allows the strainer unit to be positively snap-fit over the enlarged head of a conventional saliva ejector valve (and to thereby positively notify the dentist or hygienist that the attachment between the valve and the housing is proper). To make the strainer unit more generally useful, it is possible to provide an elongated adaptor having one end with the shape of a saliva ejector valve head and the other end shaped to mate with a high-volume valve. The preferred embodiment of a strainer unit in accordance with the invention forms the basis for a versatile modular system and can be used to connect virtually any type of saliva removal device with any conventional vacuum source. Further advantageously, and in preferred embodiments, the strainer is generally frustum-shaped, with its inlet end at the base of the frustum.
Further advantageously, in accordance with the invention an improved saliva ejector and an improved high-speed saliva aspirator are provided. In a flexible saliva ejector in accordance with the invention, a protective flange is provided adjacent to, and spaced apart from, the strainer tip that is conventionally provided. This prevents the patient's flesh from blocking all the holes through which fluids are removed from the patient's mouth, and thereby prevents the saliva ejector and the patient's flesh from being tightly and painfully urged together by the vacuum. In a saliva extractor in accordance with the invention, a protective flexible tip is secured at the distal end. This cushions the patient's flesh at the point where it is contacted by the distal end of the saliva extractor, making it less likely that the distal end of the extractor will injure the patient.
In preferred embodiments, a saliva ejector and a saliva extractor in accordance with the invention are pleated, as with locking bellows. This makes it easier for the device to maintain the shape desired without the use of stiffening wire in the wall of the device.
Still further advantageously, in accordance with the invention a new method of operating a hand-operated dental instrument (such as a high volume valve or a saliva ejector valve) is provided. In accordance with this method, a dental tool (such as a saliva ejector or a high-speed saliva aspirator in accordance with the invention, with or without a strainer unit in accordance with the invention) is packaged within a pouch, advantageously a conventional sterilizing pouch. If the dentist so desires, he can sterilize the tool and the strainer unit inside the pouch before using them. One end of the pouch is then opened to permit the instrument to be introduced into the pouch and connected with the tool. Then, the other end of the pouch is opened so the tool can be pushed out of the pouch and used in a dental operation. The tool is pushed out until the instrument is sheathed within the pouch, where it can be operated through the pouch without being physically touched by the dentist or dental hygienist. In this way